New analogs of the mitomycin antitumor antibiotics will be prepared by modification of mitomycin C and by total synthesis. The semi-synthetic analogs of the mitosane type will be prepared by way of our mitomycin C-mitomycin A interconversion. Aziridinomitosene analogs also will be prepared from mitomycin A. Totally synthetic compounds will include 1-substituted mitosenes. The new analogs will be sent to Bristol Laboratories for antitumor evaluation in P-388 murine leukemia and for determination of their toxic effects such as leukopenia. Our goal is to develop an analog that is more efficacious, but less leukopenic than mitomycin C.